The overall objectives of this project are to perform in vitro and in vivo studies in dogs with spontaneously occurring malignancies in order to design improved immunotherapeutic approaches to the treatment of tumors. More specifically, the proposed work will include: a) Development of a treatment protocol for dogs with lymphoma involving chemotherapy, total body irradiation and adoptive immunothrapy using allogenic cells, b) Studies in dogs with naturally occurring osteogeneic sarcoma involving treatment with BCG, c) Detection of tumor associated antigens in dogs with lymphoma or osteogeneic sarcoma using serological and cell mediated techniques and, d) Determination of platelet and fibrinogen survivals in dogs with lymphoma or solid tumors and their modification by drugs which inhibit platelet function.